A vehicle intended to be used in space exploration, above the atmosphere, must survive an initial ascent into the exo-atmosphere and a subsequent re-entry into and through the atmosphere. During the initial ascent, the space vehicle is accelerating from relatively low speeds to higher speeds (e.g., no higher than several hundred kilometers per hour) but is subjected to large mechanical stresses, including those generated by high frequency vibrations. During the re-entry, the space vehicle is traveling at speeds of the order of 25,000 Km/hour over the time interval during which maximum heating occurs. In the re-entry phase, this can result in temperatures up to 3000° F. on the leading edges of the vehicle for a time interval as long as about 10 minutes. The heating environment also produces very high thermal gradients, where the local temperature decreases from about 3000° F. to below 400° F. over several centimeters; this poses another challenge, where adjacent materials do not have identical thermal expansion coefficients.
What is needed is an exposed surface design and appropriate materials combination for a space vehicle that will survive the mechanical stresses induced in the initial ascent and will subsequently survive the extreme heating and mechanically stressful environment of re-entry. Preferably, the material should be relatively lightweight (ideally 10-20 lbs/ft3; up to 60 lbs/ft3) and should be modular so that exposed surface portions of the vehicle that are damaged or compromised can be easily replaced. Preferably, the system should not require precise matching of thermal expansion coefficients for the materials used in the design.